The present invention relates generally to oil seals and more particularly, to oil seals having portions which can serve as a guide to shafts being inserted through the seals, especially insertions from the air side of the seal.
Seals made according to the present invention generally have a funnel-shaped guide member, or other means to guide a shaft being inserted therethrough, and in most embodiments have the seal band on the seal with which these seals are concerned which is of a smaller diameter than the innermost diameter of the seal guide member.
These seals are also made in such a way that the insertion to be made comprises a splined shaft or the like from the air side of the seal, while these are a few oil seals which have the splined portion of the shaft received from the oil side of the seal. The present invention relates in most embodiments to seals which are intended to have a generally funnel-shaped member of slightly larger diameter of than the diameter of the seal member. Consequently, for most embodiments there is intended to be no residual contact between the guide member and the shaft, once the shaft member has been inserted within the guide. Moreover, the present invention includes a novel shipping plug or portion which will help to keep lubricant on the seal until it is inserted in the counterbore in which it is intended to be used.
Use of a seal having a funneled shaped guide for the shaft differs from the prior art insofar as the funnel shaped guide is generally on the other or air side of the seal rather than the oil side of the seal. Moreover, in most embodiments, the air side of the funnel shape has an innermost portion which was thought to be insufficient, inasmuch as there could be some damage to the shaft or to the seal while inserting the shaft therethrough. However, it has been discovered that, if the shaft is just slightly smaller than the inside of the funnel, the flexibility of the seal lip is such that the seal will not be adversely affected, while the advantage of having the funnel shaped portion with its innermost extent still free from, and not in contact with, or limited contact with the shaft, once installation has been completed.
It is therefore an object of the present invention to provide, in one embodiment, a generally funnel shaped installation guide for a shaft within an oil seal.
Another object is to provide an oil seal having a captive member attached thereto, with the captive member providing a funnel shaped installation guide made from a non-metallic material such as a plastic or like relatively stiff material.
A further object is to provide an oil seal and installation guide wherein the seal body is carried by or in relation to one member and the installation guide by another, with the two being affixed or associated in use.
A still further object of the invention is to provide an oil seal having a highly flexible portion supporting the seal on the inner portion of the seal body, and a funnel shaped plastic material being separately formed but installed in place within the seal so the components function as a unit.
A still further object is to provide a seal with a first axially extending casing member suitable for reception in a counter bore and a return portion of the casing being also provided radially inside the first casing member, thereby providing a channel or the like for the insertion of the funnel member.
Another object is to provide a composite seal having a funnel-shaped element made from a hard, thermoplastic or like material.
A further object is to provide another embodiment wherein the funnel shaped portion is entirely made from the material from which the seal casing is formed, and which is located inside the channel, is angled first radially inwardly and ultimately axially outwardly from the shaft being sealed.
A still further object of the invention is to provide another embodiment having an enlarged diameter seal casing portion, with such portion serving as the outside diameter of the casing.
Yet another object of the invention is to provide a guide for installation of the shaft which is simple and which is made from the material in which the casing is made.
An additional object is to provide a seal which has an ability to exclude additional contaminants.
Another object of the invention is to provide a guide member with a protective shipping plug designed to protect the integrity of the seal band of the oil seal, and retain lubricant until the installation is complete.
Another object of the invention is to provide an oil seal which can be inserted into a counterbore, with the oil side of the seal being received in the counterbore, and which has a funnel shaped formation intended to guide a splined shaft through the seal, preferably from the air side of the seal.